While stringing holiday lights on his home, James pulls the 4.0m string of lights up...

While stringing holiday lights on his home, James pulls the 4.0m string of lights up the side of his home so that the wire is lying perpendicular to EArth's magnetic field creating a magnetic force of 7.39X10^-4N. The cord is carrying a current of 6A. Calculate the Earth's magnetic field at James's location.